Accurate HF diagnosis before surgery tied to lower intraoperative fluid administration and reduced risk of postoperative AKI: Study

Recent research paper published in the British Journal of Anaesthesia focuses on the association between accurate diagnosis of heart failure (HF) before major noncardiac surgery, intraoperative fluid management, and postoperative acute kidney injury (AKI). The study was conducted at a single academic hospital from 2015 to 2019 and involved adult patients undergoing major noncardiac surgeries. A preoperative clinical diagnosis of HF was identified using keywords in the preoperative assessment or diagnosis codes. Medical records were reviewed by a multispecialty panel to establish an adjudicated HF reference standard. The primary outcome was the volume of intraoperative fluid administered, while the secondary outcome was postoperative AKI.

Results and Patient Comparisons

The results showed that an accurate diagnosis of HF before surgery was associated with lower intraoperative fluid administration (470 ml less) and a reduced risk of postoperative AKI (adjusted odds ratio of 0.39). Patients without a clinical diagnosis of HF but with an adjudicated diagnosis (false negatives) tended to have preserved left ventricular ejection fractions and fewer comorbidities compared to those with accurate diagnoses (true positives). On the other hand, patients incorrectly diagnosed with HF (false positives) had lower ejection fractions, more comorbidities, and were more likely to undergo thoracic surgeries.

Impact on Practice Patterns and Outcomes

The impact of accurate HF diagnosis extended to intraoperative practice patterns and postoperative outcomes. Accurate diagnoses were linked to reduced sedative exposure, increased use of arterial line monitoring and inotropes, lower maximum postoperative lactate levels, and shorter postoperative lengths of stay. Additionally, accurate HF diagnosis correlated with fewer vasopressor infusions for patients without adjudicated HF.

Recommendations for Improving Diagnostic Accuracy

The study highlighted the importance of targeted efforts to improve preoperative HF diagnostic accuracy to enhance perioperative outcomes. It also identified factors associated with diagnostic inaccuracies, such as preoperative laboratory and imaging studies, comorbidities, and surgical procedures. The findings suggested that missing HF diagnoses were not just documentation deficiencies but could have actual diagnostic implications affecting patient outcomes.

Study Limitations and Implications

The study had some limitations, including its observational nature, limited generalizability to other institutions, and focusing only on intraoperative fluid administration as the primary outcome. However, the results underscored the significance of accurate HF diagnosis in improving patient care and outcomes during major noncardiac surgeries. The authors emphasized the need for further research to explore strategies for enhancing diagnostic accuracy and optimizing perioperative management for patients with HF.

Key Points

- The study examined the association between accurate diagnosis of heart failure (HF) prior to major noncardiac surgery, intraoperative fluid management, and postoperative acute kidney injury (AKI) in adult patients. - Preoperative clinical diagnosis of HF was established using keywords and diagnosis codes, with medical records reviewed by a multispecialty panel to confirm the diagnosis.

- Patients accurately diagnosed with HF before surgery received less intraoperative fluid (470 ml less) and had a lower risk of postoperative AKI (adjusted odds ratio of 0.39).

- Patients with false negative diagnoses had preserved left ventricular ejection fractions and fewer comorbidities compared to true positive cases, while false positive diagnoses were associated with lower ejection fractions, more comorbidities, and a higher likelihood of thoracic surgeries.

- Accurate HF diagnosis was linked to improved intraoperative practice patterns, including reduced sedative exposure, increased use of arterial line monitoring and inotropes, lower postoperative lactate levels, and shorter postoperative lengths of stay.

- The study recommended targeted efforts to enhance preoperative HF diagnostic accuracy to optimize perioperative outcomes, while identifying factors contributing to diagnostic inaccuracies and emphasizing the impact of missed HF diagnoses on patient outcomes.

Reference –

Benjamin Deniau et al. (2024). Accurate Diagnosis Of Heart Failure And Improved Perioperative Outcomes.. *British Journal Of Anaesthesia*, 134 1, 1-4. https://doi.org/10.1016/j.bja.2024.10.003.